1. Technical Field
This disclosure relates to wafer-level lens systems having wide viewing angles and, more particularly, to five-aspheric-surface wafer-level lens systems having wide viewing angles.
2. Discussion of Related Art
Small digital camera modules are growing in popularity and importance. In general, portable electronic devices, such as mobile telephones, tablets and notebook computers, now include small digital camera modules. A lens having short overall length is desirable for these common applications for small digital camera modules. Conventionally, the lens of a small digital camera module is a molded one-piece plastic lens. Such a conventional plastic lens allows only two surfaces with one material.
The viewing angle of a camera module is typically between about 60 degrees and about 70 degrees. There are certain restrictions to producing a lens having a viewing angle larger than 70 degrees, while maintaining a short overall lens length. For example, optical aberrations generated by the lens cannot be tolerated in typical present-day image sensors, which exhibit greatly improved resolution. Therefore, it is now desirable to have a lens system with a large viewing angle and short overall length of lens, and with an optical performance, e.g., optical aberration, that is compatible with image sensors having enhanced resolution.
A wafer-level lens is typically manufactured by forming a plurality of lenses on a wafer or substrate. The lenses are typically formed by molding and curing a lens material on the wafer or substrate. After the lenses are cured, the wafer or substrate is cut into pieces, with each piece containing at least one lens. A wafer-level lens may be formed by stacking more than one substrate together, with each substrate including at least one lens. Multiple lenses can be formed in the multiple substrates in registration with each other, such that, when the lenses and substrates are cut into pieces, One or more of the lenses can actually include multiple stacked lenses. Hence, a wafer-level lens system may include multiple substrates and multiple lenses.